In related art, an air conditioning controlling system includes an air conditioner such as a fan coil unit (FCU), in which cold/hot water is supplied to a heat exchanger of the air conditioner. A flow rate control valve is provided in a supply passage of cold/hot water to the heat exchanger of the air conditioner, and an air conditioning controlling device (controller) is provided as a device for controlling an opening of the flow rate control valve.
The air conditioning controlling device controls the opening of the flow rate control valve so that a difference between a measured value of a room temperature in a space to be controlled which receives supply of conditioned air from the air conditioner and a setting value of the room temperature set with respect to the room temperature becomes zero. The supply of cool/hot water to the heat exchanger of the air conditioner is controlled accordingly, and the temperature of conditioned air from the air conditioner to the space to be controlled is adjusted (for example, refer to Japanese Unexamined Patent Publication No. JP-A-2008-45855)
However, in the above air conditioning controlling system, the flow rate control valve provided in the supply passage of cold/hot water realizes the flow rate control by changing the opening area of a plug provided in the flow passage as a valve element to thereby generate pressure loss. The energy corresponding to the pressure loss generated at that time has been discarded wastefully as heat. There is also another problem that high power is necessary for driving the valve element.
In Japanese Unexamined Patent Publication No. JP-A-2012-241659 (JP '659), a power generation device using a residual pressure of a water supply facility which generates power while reducing pressure of tap water in a water distribution pipeline is disclosed. In the power generation device using the residual pressure of the water supply facility, a hydraulic turbine provided in the water distribution pipeline through which tap water flows and a power generator generating the power by the rotation of the hydraulic turbine are provided, in which the pressure on a downstream side of the hydraulic turbine is reduced by a rotation resistance of the hydraulic turbine caused by a power generation load of the power generator.
In JP '659, a technique in which a torque of the power generator is controlled so that the flow rate of the hydraulic turbine reaches a target flow rate is disclosed as Example 2. Hereinafter, the technique will be called the technique of JP '659.
Specifically, an angular velocity of the hydraulic turbine is detected, an estimated flow rate of the hydraulic turbine is calculated from the angular velocity of the hydraulic turbine and a torque command value, a pressure reducing amount is estimated from the estimated flow rate, a torque command value for realizing a target flow rate is calculated from the estimated pressure reducing amount, a difference between the estimated flow rate and the target flow rate is calculated, feedback items of the flow rate are added to the torque command value, a difference between a target angular velocity and the angular velocity is calculated, feedback items of the angular velocity are added to the torque command value, and the torque command value to which feedback items of the flow rate and the angular velocity are added is outputted to an inverter (refer to paragraphs [0043] to [0049], description concerning FIG. 7 and FIG. 8 in JP '659)
In the technique of JP '659, the target flow rate is a target value corresponding to the target pressure reducing amount (pressure difference of the hydraulic turbine between the upstream side and the downstream side), which is a given value to be determined so as to correspond to the water supply facility in the same manner as the target pressure reducing amount.
That is, in the technique of JP '659, it is assumed that the value of the target flow rate is a fixed and does not vary, and the torque of the power generator is controlled so that the estimated flow rate corresponds to the target flow rate determined as an invariable value. That is, in JP '659, there is no intention to control the actual flow rate by changing the value of the target flow rate, and an object thereof is just to take out electrical energy by using the residual pressure of the water supply facility.
There is disclosed in Japanese Unexamined Patent Publication No. JP-A-5-106753 (JP '753) a valve with a built-in power generating device including a power generating device having a rotor arranged in a valve box and rotated by fluid energy at the time of opening a valve element and a power generator generating power by the rotation of the rotor, a power storage device storing power generated by the power generating device, an electric motor activated by an output voltage of the power storage device, and a power transmission mechanism transmitting the rotation output of the electric motor to a valve rod, in which an opening/closing device selecting a forward/reverse rotation and a stop of the electric motor to be executed is provided in an electric path which electrically connects the power storage device and the electric motor.
In the valve with the built-in power generating device disclosed in JP '753, the “power generating device” having the rotor and the power generator and the “valve device” controlling circulation and blocking of the fluid are provided in the valve so as to be separated from each other, therefore, a number of component parts are necessary and the size is increased in a flow direction of the fluid. Also in JP '753, there is no intention to control the actual flow rate by changing the value of the target flow rate, and an object thereof is just to open and close the valve element automatically by using the fluid energy generated at the time of opening the valve element to thereby reduce the energy loss. Though the valve element is configured to be opened and closed automatically by using the generated power, high power is necessary as the valve element is used.
The invention has been made for solving the above problems and an object thereof is to provide a turbine-type flow rate controlling device capable of saving power by controlling the actual flow rate without using a valve element.
Another object thereof is to provide a turbine-type flow rate controlling device capable of achieving reuse of energy and contributing to energy saving by collecting part of energy as electrical energy which has been discarded as heat at the time of controlling the actual flow rate.
Further another object is to provide a turbine-type flow rate controlling device capable of properly controlling a torque of a power generating portion continuously even when a position sensor for detecting a magnetic pole position of a turbine (a position of a magnetic pole of a magnet incorporated in the turbine) fails or detection accuracy is deteriorated.